Softener for silk and process for making same



Patented Nov. 20,1928.

UNITED STATES 1,691,994 PATENT OFFICE.

ROBERT E. ROSE, or PENNS GROVE, NEW JERSEY, ASSIGNOLR. TO E. I. DU PONT DE NEMOURS & COMPANY, or WILMINGTON. DELAWARE, A CORPORATION or DELA- WARE.

. No Drawing.

This invention relates to a process and product to be employed in the art of manufactuim ing genuine or artificial silk textiles of supe rior quality and Weight.

In the manufacture of tin Weighted genuine silk and often, also, in the manufacture of artificial silk it is desirable to use a softener or lubricant to impart to the fabric the proper texture, appearance, durability and feel. It is customary toemploy in this capacity sulfonated castor oil.

I have found that the products of the reaction which occurs when sulfonated castor oil is treated with a substituted guanidine, which products are most probably, and will hereinafter be referred to as, the guanidine salts of the sulfonated oil, are far superior as softeners to the ordinary sulfonated castor oil. They are most excellent for treating tin weighted genuine silk and are also well adapted for treating artificial silk. These salts have the advantage that they dry better than the sulfonated oil, and do not show as reat a tendency to spot the fabric. Also, iliey act as a better lubricant than anything hitherto employed in this art, so far as we are aware. Furthermore, their presence in the fibre seems to enable the silk to absorb more moisture and thereby appreciate in weight.

In presenting a preferred example of my process I have chosen as the specific guanidine used for the preparation of the softener, diortho-tolyl-guanidine, but the substituted guanidines generally and their various isomers are adapted for use. Thus diphenyl guanidine may be employed or even triphenyl,

'but the tri-substituted guanidines give rise to products that aretoo insoluble, and do'not emulsify well enough to yield the best results.

The following procedure has been used with very good success, but is only one example of my method: I

10 lbs. of the'ammonium salt of sulfonated castor oil are heated to about C. (the temperaturema be varied within a wide range). Into the liquid are stirred 2 lbs. di-ortho-tolylguanidine. The mass is now heated until it becomes entirely homogeneous which occurs in a few min-utes heating being continued so that the temperature may rise to 90 C. at the end :of thee erat-ionp Some ammonia is given OE and t e liquid is ready for use.

The method of preparation as well as the particular guanidine employed may be varied; For example, it is obviousthat the sulfonated SOIETENER FOR SILK AND P ROCESS FOR MAKING SAME.

Application filed November 17, 1925. Serial No. 69,711.

castor oil instead of its ammonium salt may be used, this being neutralized by the addit1on of guanidine and then made slightly alkaline with ammonia, or it is possible to use the sodium salt of the sulfonated castor oil and treat. this with a saltiof the guanidine chosen such as the chloride. In this case sodium chloride or other sodium salt is formed, which sometimes crystallizes out but the product is essentially the same as in the other examples.

Also the amount of guanidine employed can be varied over a considerable range without alter ng the nature of the softener because the quanrdme which does not react to form a salt Wlll simply remain in solution.

The softener, when prepared by any of the methods indicated above, may be applied to the s1lk 1n any appropriate manner. For example, it may be applied after the silk is dyed by soaking the fibre in an emulsion of the softener for 10 minutes at a temperature of 90 F. The amount of softener employed in a given case will depend on the feel which the dyer wishes to impart to the finished silk. An emulsion containing about 5'ozs. (for 10 gallons) of the softener is the average quan- By the term silk, wherever employed throughout the specification and claims w1th-. out the modifiers artificial or genuine, it s lntended to designate both varieties, genume and artificial.

I claim as my invention:

1. A softener for silk. comprising a guanidme salt of sulfonated castor oil.

2. rksoftener for silk comprising an arylguanidine salt of sulfonated castor oil. I

3. A softener for silk comprising a tolyl-- guanidine salt of sulfonated castor oil.

. 4. The di-ortho-tolyl-guanidine salt of sulfonated castor oil.

5. The process of softening silk which comprlses th step of treating the fibre with a tolyl-guanidine salt of sulfonated castor oil.

6. The process of softening tin weighted s1lk which'comprises the step of treating the weighted silk with an emulsion of an aryl guanidine salt of sulfonated castor oil. t 7. The process of preparing a softener for silk which comprises adding a substituted guanidine to a compound comprising a sulfonated residue of ricinoleic acid.

8. The process of preparing a softener for s lk which comprises the step of adding to a compound comprising sulfonated castor oil,

di-ortho-to1yl-guanidine.

9. The process of preparing a softener for silk which comprises the step of adding to a 5 compound comprisinga salt of sulfonated castor oil, an aryl-guanidine.

10; A silken textile containing as a softener a guanidine salt of :sulfonated castor oil.

11. A process of lubricating and softenin 10 silk which comprises adding a substitute uanidine to a compound comprising sulonated castor 011 and soakln the Sllk'lll an emulsion of the resultmg pro 'uct.'

13. As a new compound, the roduct obtainable by reacting sulfonate castor oil with di-ortho-toly1-guanidine.

14. A silken textile impregnated with the product obtainable by reacting a sulfonated residue of ricinoleic acid with a substituted guanidine.

In testimony whereof I aifix m signature. I

ROBERT ROSE. 

